It is well known that the ubiquitous advent of mobile telephones has had a beneficial impact on safety and health since, in case of emergency situations, mobile telephones allow setting of emergency calls instantly and at virtually any location.
The capabilities of modern mobile phones have led to further developments intended to improve the user's health and safety, or at least the reliability and swiftness, with which help or first-aid can be called. One such improvement are mobile phones enhanced with an “one push” emergency-only-key. Such a mobile phone is suggested for instance in Japanese patent application JP 7 183970, which proposes a portable cellular phone capable of activating an emergency call if the user presses the emergency-only-key. When this key is pressed, a line is connected to a specific destination, which is stored in the phone as emergency call receiver, and information, such as the user's details and the address of the current base station (network cell), is transmitted automatically to the destination. Another mobile phone of this kind is known e.g. from U.S. Pat. No. 5,365,570.
A drawback of this approach is that, in order to set off an emergency call, relatively conscious and controlled user interaction is required, which under certain circumstances—e.g. when a user feels panic or is incapable to properly handle the phone—may prove difficult if not impossible. Moreover, this approach is prone to generate a majority of unintended emergency calls due to inadvertent or accidental pushing of the dedicated emergency-only-key.
An alternative solution that allows more easily setting off an emergency call and/or sounding an acoustic alarm, e.g. an “anti mugging alarm”, by means of a mobile telephone is disclosed in European patent no. 0 920 225.
The telephone according to EP 0 920 225 comprises a housing, a detection circuit configured for being interrupted from outside the housing, a strap member and an electronic control unit. The strap member cooperates with the detection circuit for interrupting the detection circuit upon pulling the strap member off the housing. The control unit is configured to monitor interruption of the detection circuit, to activate an emergency mode in case of interruption and to automatically perform emergency operations in this emergency mode. The detection circuit of EP 0 920 225 includes a first conductor that is grounded and a second conductor that is pulled up to higher potential. In the absence of an emergency, the first conductor and the second conductor, which are configured in the form of springs, are constantly in contact with each other so that the control unit measures a ground potential. The strap itself is wrapped immediately around the spring-like first and second conductors. When the user pulls the strap from either conductor, they are brought out of contact. Consequently, in the event of an emergency, the emergency input detection signal changes to pull-up potential so that a pulse is generated that is detected by the electronic control unit. So long as an emergency input can be entered by simple removal of a strap, a user can instantaneously indicate an emergency through use of the portable cellular phone according to EP 0 920 225.
Whereas the approach of EP 0 920 225 facilitates user activation of an emergency mode, its configuration has several drawbacks. Among others, it is not readily suitable as a retrofit or optional enhancement for mass production mobile phones, in case of which not every user may desire the presence of a strap and a “rapid-action” emergency feature. Furthermore, the suggested approach is also inadequate to allow discerning inadvertent or accidental activation from a true emergency situation.
Japanese patent application JP 11 284 711 also discloses a mobile telephone equipped for activation of an emergency mode, with a housing, a detection circuit configured for being triggered from outside and a strap member for triggering. This phone also has appears to have an electronic control unit that is configured 1) to monitor triggering of the detection circuit, 2) to activate an emergency mode accordingly, and 3) to automatically perform emergency operations in such an emergency mode. As opposed to EP 0 920 225, the strap member according to JP 11 284 711 does not only have a strap but also a first mechanical connector attached to the strap, Correspondingly, there is a second mechanical connector on the housing that cooperates with the first connector for fastening the strap member to the housing. When the strap is pulled off, the strap-side connector is detached so that an annular conductor provided on a retainer-shaped base part of the strap member bridges a detection circuit. Whereas this design might improve avoidance or discerning of inadvertent or accidental activation, it still does not enable a low-cost retrofit or optional mass production enhancement for mobile phones.